【摘要】 利用液滴外延技术在Al0. 4Ga0. 6As表面制备了纳米结构并用原子力显微镜进行表征,发现纳米结构的密度随金属Ga沉积量的增加呈先增加后减小再增加的趋势。这种密度异常变化的现象,主要是由于液滴之间相互扩散并最终形成连续的平坦层,随着沉积量的继续增加,新吸附的Ga原子在平坦层上面形成新的Ga液滴,从而导致了密度的降低。此外,纳米结构的孔深、孔径、环高和盘径几何特征尺寸随着沉积量的增加而增加,且在表面[1-10]和[110]两个方向上纳米结构中的量子环以及盘状结构的形貌特征呈现各向异性。更多还原

【Abstract】 In this paper,the nanostructures were fabricated on the surface of Al_0.4Ga_0.6As by droplet epitaxy and characterized by atomic force microscopy. It was found that the density of nanostructures increased first,then decreased and then increased with the increase of metal Ga deposition. The abnormal phenomenon of density change is mainly due to the mutual diffusion of the droplets and form a continuous flat layer finally. As the deposition amount increase,the newly adsorbed Ga atoms form new Ga droplets on the flat layer,therefore leads to a decrease in density. In addition,the nanohole depth and size,ring height and diffusion halos diameter geometric feature size of the nanostructures increase with the deposition amount,and the quantum rings of nanostructures in the two directions [1-10] and [110] and the topography of the diffusion halo structure exhibits anisotropy.更多还原